The IFT80/Hedgehog Pathway Regulates the Osteogenic-adipogenic Differentiation of Bone Marrow Mesenchymal Stem Cells.

BACKGROUND: Steroid-induced avascular necrosis of the femoral head (SANFH) is a typical refractory disease that often progresses irreversibly and has a high disability rate. Numerous studies have confirmed that abnormal osteogenic-adipogenic differentiation of bone marrow mesenchymal stem cells (BM-MSCs) is one of the major factors of SANFH. However, the mechanism remains to be elucidated. OBJECTIVES: This study aimed to investigate the mechanism and effect of the IFT80/Hedgehog-mediated osteogenic-adipogenic differentiation of BM-MSCs in SANFH. METHODS: Femoral head specimens of SANFH patients and femoral neck fractures (FNF) patients were collected to detect the expression of IFT80, Shh and osteogenic-adipogenic differentiation-related genes by immunohistochemistry (IHC), western blot (WB) and Reverse Transcription Quantitative Polymerase Chain Reaction (RT-qPCR). Based on the rabbit SANFH model, the mRNA expression and protein level of IFT80 and Shh were detected by RT-qPCR and WB. After the osteogenic/adipogenic differentiation based on rabbit BM-MSCs, the IFT80, Gli1, PPAR-γ, and Runx2 expression were detected. Differences in alkaline phosphodiesterase activity, calcium nodule, quantification/distribution of lipid droplets, expression of IFT80/Hedgehog axis, and the level of osteogenic- adipogenic associated factors were determined after IFT80 overexpression. RESULTS: RT-qPCR, WB and IHC revealed that IFT80 and Shh lowly expressed in the osteoblasts and intra-trabecular osteocytes at the edge of trabeculae and in the intercellular matrix of the bone marrow lumen in the SANFH specimens. The Runx2 expression was low, while the PPAR-γ expression was high in both human specimens and animal models of SANFH, suggesting that the balance of osteogenic-adipogenic differentiation was dysregulated. Rabbit BM-MSCs with stable overexpression of IFT80 showed increased alkaline phosphatase activity after induction of osteogenic differentiation, increased calcium nodule production, and decreased adipogenesis after induction of adipogenic differentiation. CONCLUSION: There is a dysregulation of the balance of osteogenic-adipogenic differentiation in SANFH. IFT80 may inhibit adipogenic differentiation while promoting osteogenic differentiation in rabbit BM-MSCs by activating the Hedgehog pathway.

Verification of cuproptosis-related diagnostic model associated with immune infiltration in rheumatoid arthritis.

Background: Rheumatoid arthritis (RA) is a chronic autoimmune disease closely related to inflammation. Cuproptosis is a newly discovered unique type of cell death, and it has been found that it may play an essential role in the occurrence and development of RA. Therefore, we intend to explore the potential association between cuproptosis-related genes (CRGs) and RA to provide a new biomarker for the treatment and prognosis of RA. Methods: Download GSE93777 datasets from the GEO database. Variance analysis was performed on the CRGs that had been reported. Then, the random forest (RF) model and nomogram of differentially expressed CRGs were constructed, and the ROC curve was used to evaluate the accuracy of the diagnostic model. Next, RA patients were subtyped by consensus clustering, and immune infiltration was analyzed in each subgroup to confirm the correlation between CRGs and abundance of immune cells. The expression levels of CRGs were verified by qRT-PCR. Results: Eight differentially expressed CRGs (DLST, DLD, PDHB, PDHA1, ATP7A, CDKN2A, LIAS, DLAT) were screened out by differential analysis to construct an RF model. The ROC curve proved that this model had good diagnostic accuracy. Based on the above eight significant CRGs, a nomogram was built to predict effective and high-precision results. The consensus clustering method identified two CRG patterns. Most of the immune cells were enriched in cluster A, indicating that cluster A may be related to the development of RA. Finally, qRT-PCR verified the expression of eight key genes, further confirming our findings. Conclusion: The diagnosis model of RA based on the above eight CRGs has excellent diagnostic potential. Based on these, patients can be divided into two different molecular subtypes; it is expected to develop a new treatment strategy for RA.

Exosome-mediated miR-144-3p promotes ferroptosis to inhibit osteosarcoma proliferation, migration, and invasion through regulating ZEB1.

BACKGROUND: Osteosarcoma (OS) is the most prevalent orthopedic malignancy with a dismal prognosis. The high iron absorption rate in OS cells of patients suggests that ferroptosis may be related to the progression of OS, but its potential molecular regulatory role is still unclear. Based on the ability to couple with exosomes for targeted delivery of signals, exosome-derived micro ribonucleic acids (miRNAs) can potentially serve as diagnostic biomarkers for OS. METHODS: We identified ferroptosis-related miRNAs and messenger ribonucleic acids(mRNAs) in OS using bioinformatics analysis and performed survival analysis. Then we measured miRNA expression levels through exosome microarray sequencing, and used RT-qPCR and IHC to verify the expression level of miR-144-3p and ZEB1. Stable gene expression cell lines were fabricated for in vitro experiments. Cell viability, migration and invasion were determined by CCK-8 and transwell experiment. Use the corresponding reagent kit to detect GSH/GSSG ratio, Fe2+ level, MDA level and ROS level, and measure the expression levels of GPX4, ACSL4 and xCT through RT-qPCR and WB. We also constructed nude mice model for in vivo experiments. Finally, the stability of the miRNA/mRNA axis was verified through functional rescue experiments. RESULTS: Low expression of miR-144-3p and high expression of ZEB1 in OS cell lines and tissues was observed. Overexpression of miR-144-3p can promote ferroptosis, reduce the survival ability of OS cells, and prevent the progression of OS. In addition, overexpression of miR-144-3p can downregulate the expression of ZEB1 in cell lines and nude mice. Knockdown of miR-144-3p has the opposite effect. The functional rescue experiment validated that miR-144-3p can regulate downstream ZEB1, and participates in the occurrence and development of OS by interfering with redox homeostasis and iron metabolism. CONCLUSIONS: MiR-144-3p can induce the occurrence of ferroptosis by negatively regulating the expression of ZEB1, thereby inhibiting the proliferation, migration, and invasion of OS cells.

Characteristics of antibiotic resistance genes and microbial community distribution in Wanfeng Lake, upper Pearl River, China.

Wanfeng Lake, a highland lake in the upper part of the Pearl River Basin, China, has long been disturbed by aquaculture and human activities, resulting in the accumulation of antibiotics and antibiotic resistance genes (ARGs), which pose a major threat to humans and animals. In this study, 20 antibiotics, 9 ARGs, 2 mobile genetic elements (intl1 and intl2), and microbial community structure were investigated in Wanfeng Lake. The results of the study showed that the total concentration of antibiotics in surface water was 372.72 ng/L, with ofloxacin (OFX) having the highest concentration (169.48 ng/L), posing a high ecological risk to aquatic organisms. The total concentration of antibiotics in sediments was 235.86 ng/g, with flumequine (FLU) having the highest concentration (122.54 ng/g). This indicates that the main type of antibiotics in Wanfeng Lake are quinolones. QPCR analysis results of the relative abundance of ARGs in both surface water and sediments showed that sulfonamide resistance genes > macrolide resistance genes > tetracycline resistance genes > quinolone resistance genes, indicating that sulfonamide resistance genes were the dominant type. The metagenomic results showed that the predominant microorganisms in the sediment under the phylum level were Planctomycetes, Proteobacteria, Euryarchaeota, and Chloroflexi. Pearson's correlation analysis showed a significantly positive correlation between antibiotics and environmental factors with ARGs in Wanfeng Lake and a significant positive correlation between antibiotics and ARGs with microorganisms in sediments. This suggests that there is a potential pressure of antibiotics on ARGs, while microorganisms provide the driving force for the evolution and spread of ARGs. This study provides a basis for further research on the occurrence and spread of antibiotics and ARGs in Wanfeng Lake. A total of 14 antibiotics were detected in surface water and sediments. OFX poses a high ecological risk in all points of surface water. Antibiotics and ARGs were significantly positively correlated in Wanfeng Lake. Antibiotics and ARGs in sediments were positively correlated with microorganisms.

Batch and semi-continuous experiments examining the sludge mesophilic anaerobic digestive performance with different varieties of rice straw.

Anaerobic co-digestion of excess sludge (ES) and different varieties of rice straw including indica rice straw (IRS), japonica rice straw (JRS) and glutinous rice straw (GRS) was investigated in batch and semi-continuous experiments. The batch experiment results showed that the GRS addition presents the highest hydrolysis and methanogenesis rates, its cumulative methane yield (CMY) was 305.75 mL/g VS and its average methane content was 60.56%. After digestion, the structure of GRS was almost completely destroyed, which was beneficial to the degradation of lignocellulose. The digestive process is affected by the abundance of Actinobactereria, Proteobacteria, Methanosaetae and Methanosarcina. The results of semi-continuous digestion were similar to batch digestion. In addition, the addition of GRS increased TN concentration in biogas residue and TP concentration in biogas slurry, but was not conducive to the subsequent dehydration of sludge.

Reconfigurable photonic ultrawideband pulse generation from an optically injected semiconductor laser.

We demonstrate reconfigurable photonic ultrawideband (UWB) pulse generation by injecting a phase-modulated optical wave into a semiconductor laser. By adjusting the injection power level and phase modulation depth, the photonic UWB generator is capable of generating either a single-optical-carrier monocycle or power-efficient UWB pulses. A UWB pulse with spectral power efficiency (SPE) of 36.10% has been achieved by optimizing the injection parameters. Transmission in an 8.4 km single mode fiber results in a degradation of SPE to 27.55% without significant pulse distortion.

Ultrawideband monocycle pulse generation based on delayed interference of π/2 phase-shift keying signal.

We propose a scheme to generate ultrawideband (UWB) monocycle pulses using delayed interference of a π/2 phase-shift keying (PSK) signal. The PSK signal is generated with an optical phase modulator. A fiber-based delay interferometer is used to provide the delay together with a ±π/2 phase shift between the signals in its two arms before the interference. The two opposite phase shifts correspond to the generation of a pair of polarity-reversed UWB monocycle pulses. The full width at half maximum of the pulses is ~68 ps and the 10 dB fractional bandwidth is 168%.

Bit-rate variable DPSK demodulation based on cascaded four-wave mixing.

We report a demodulator for DPSK signals at variable bit rates based on cascaded four-wave mixing (FWM). The demodulation utilizes two FWM processes in a photonic crystal fiber (PCF) with in-between dispersion in a chirped fiber Bragg grating (CFBG). The first FWM generates a wavelength-tunable idler carrying phase information of the signal. A tunable optical delay between the signal and the idler is then introduced by dispersion. The signal, the idler, and the pump are reflected by the CFBG with a reflectance of 99% back to the PCF to initiate the second FWM process. In the second FWM, the phase relationship between the signal and the one-bit-delayed idler determines an amplification or attenuation of the idler, converting phase modulation to intensity modulation. Error-free demodulations have been successfully demonstrated for both NRZ and RZ-DPSK signals at 5 and 10 Gb/s.

Reconfigurable two-channel demultiplexing using a single baseband control pulse train in a dispersion asymmetric NOLM.

We demonstrate a unique solution to use a one-pulse control to achieve simultaneous two-channel all-optical demultiplexing that usually requires a two-pulse control or a two-step operation based on the conventional approaches. By applying a dispersion asymmetric nonlinear optical loop mirror (DA-NOLM) to introduce cross phase modulation (XPM) in both the clockwise (CW) and the counter clockwise (CCW) propagating branches, we have demonstrated reconfigurable, error-free 40-to-10 Gb/s two-channel demultiplexing (DEMUX) for OTDM OOK signals. Switchable operation between two-channel and single-channel DEMUX is also realized based on the proposed all-optical DEMUX configuration.

Photonic crystal fiber based Mach-Zehnder interferometer for DPSK signal demodulation.

We demonstrate a novel fiber-based in-line DPSK demodulator using an in-fiber Mach-Zehnder interferometer (MZI). The device is fabricated by mismatch splicing of a photonic crystal fiber (PCF) with standard single mode fibers. The spectral characteristics at different PCF lengths are analyzed. The envelope of the interference fringes show a period that is inversely proportional to the PCF length, and is attributed to the periodic coupling between the core mode and the cladding mode. Error free demodulations of 10-Gb/s RZ- and NRZ-DPSK signals have been demonstrated using the in-fiber PCF-MZI demodulator with only 3-m PCF to introduce 91-ps delay. Wideband DPSK demodulation has also been achieved.

Emission spectrum broadening of Nd:YVO(4) with femtosecond laser pulse processing.

The observation of emission spectrum broadening of Nd:YVO(4) by femtosecond laser pulse processing is reported. This result opens the possible way of sub-ps pulse generation from Nd ion doped crystals with better physical qualities than that of glass based laser gain materials.